Alec using the arc spraying device

Make Metal Rain With Thermal Spraying

November 6, 2025 by 2 Comments

For those of us hackers who have gone down a machining rabbit hole, we all know how annoying it can be to over-machine a part. Thermal spraying, while sounding sci-fi, is a method where you can just spray that metal back on your workpiece. If you don’t care about machining, how about a gun that shoots a shower of sparks just to coat your enemies in a layer of metal? Welcome to the world of thermal spraying, led by the one and only [Alec Steele].

There are three main techniques shown that can be used to coat using metal spools. The first, termed flame spraying, uses a propane flame and compressed air to blast fine drops of molten metal onto your surface. A fuel-heavy mixture allows the metal to remain unoxidized and protect any surface beneath. Perhaps one of the most fun to use is the arc method of thermal spray. Two wires feed together to short a high current circuit; all it takes from there is a little pressured air to create a shower of molten metal. This leaves the last method similar to the first, but uses a powder material rather than the wires used in flame spraying.

As with much crazy tech, the main uses of thermal spraying are somewhat mundane. Coating is applied to prevent oxidation, add material to be re-machined, or improve the mechanical resistance of a part. As expensive as this tech is, we would love to see someone attempt an open-source version to allow all of us at Hackaday to play with. Can’t call it too crazy when we have people making their own X-ray machines.

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Spectravideo Computers Get A Big Upgrade

November 5, 2025 by No comments

Spectravideo is not exactly the most well-known microcomputer company, but they were nevertheless somewhat active in the US market from 1981 to 1988. Their computers still have a fanbase of users and modders. Now, as demonstrated by [electricadventures], you can actually upgrade your ancient Spectravideo machine with some modern hardware.

The upgrade in question is the SVI-3×8 PicoExpander from [fitch]. It’s based on a Raspberry Pi Pico 2W, and is built to work with the Spectravideo 318 and 328 machines. If you’re running a 328, it will offer a full 96kB of additional RAM, while if you’re running a 318, it will add 144 kB more RAM and effectively push the device up to 328 spec. It’s also capable of emulating a pair of disk drives or a cassette drive, with saving and loading images possible over Wi-Fi.

It’s worth noting, though, that the PicoExpander pushes the Pico 2W well beyond design limits, overclocking it to 300 MHz (versus the original 150 MHz clock speed). The makers note it is “bleeding edge” hardware and that it may not last as long as the Spectravideo machines themselves.

Design files are available on Github if you want to spin up your own PicoExpander, or you can just order an assembled version. We’ve seen a lot of other neat retrocomputer upgrades built around modern hardware, too. Video after the break.

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A Pentium In Your Hand

November 5, 2025 by 1 Comment

Handheld computers have become very much part of the hardware hacker scene, as the advent of single board computers long on processor power but short on power consumption has given us the tools we need to build them ourselves. Handheld retrocomputers face something of an uphill struggle though, as many of the components are over-sized, and use a lot of power. [Changliang Li] has taken on the task though, putting an industrial Pentium PC in a rather well-designed SLA printed case.

Aside from the motherboard there’s a VGA screen, a CompactFlash card attached to the IDE interface, and a Logitech trackball. As far as we can see the power comes from a USB-C PD board, and there’s a split mechanical keyboard on the top side. It runs Windows 98, and a selection of peak ’90s games are brought out to demonstrate.

We like this project for its beautiful case and effective use of parts, but we’re curious whether instead of the Pentium board it might have been worth finding a later industrial PC to give it a greater breadth of possibilities, there being few x86 SBCs. Either way it would have blown our minds back in ’98, and we can see it’s a ton of fun today. Take a look at the machine in the video below the break.

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Better 3D-Printed Bridges Are Possible, With The Right Settings

November 5, 2025 by 3 Comments

The header image above shows a completely unsupported 3D-printed bridge, believe it or not. You’re looking at the bottom of the print. [Make Wonderful Things] wondered whether unsightly unsupported bridges could be improved, and has been busy nailing down remarkably high-quality results by exhaustive testing of different settings.

It all started when they thought that unsupported bridges looked a lot as though they were made from ropes stretched between two points. Unlike normal layers, these stretched extrusions didn’t adhere to their neighbors. They are too far apart from one another, and there’s no “squish” to them. But could this be overcome?

His experiments centered mainly around bridge printing speed, temperature, and bridge flow. That last setting affects how much the extrusion from the hot end is adjusted when printing a bridge. He accidentally increased it past 1.0 and thought the results were interesting enough to follow up on; it seemed that a higher flow rate when printing a bridge gave the nudge that was needed to get better inter-line adhesion. What followed was a lot of testing, finally settling on something that provided markedly better results than the stock slicer settings. Markedly better on his test pieces, anyway.

BF = Bridge flow, BS = Bridge printing speed (in mm/sec)

The best results seem to come from tweaking the Bridge Flow rate high enough that extrusions attach to their neighbors, printing slowly (he used 10 mm/sec), and ensuring the bridged area is as consistent as possible. There are still open questions, like some residual sagging at corners he hasn’t been able to eliminate, but the results otherwise look great. And it doesn’t even require laying one’s printer on its side!

All the latest is on the project page where you can download his test models, so if you’re of a mind to give it a try be sure to check it out and share your results. Watch a short video demonstrating everything, embedded just under the page break.

Thanks to [Hari] for the tip!

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Hacking Buttons Back Into The Car Stereo

November 5, 2025 by 15 Comments

To our younger readers, a car without an all-touchscreen “infotainment” system may look clunky and dated, but really, you kids don’t know what they’re missing. Buttons, knobs, and switches all offer a level of satisfying tactility and feedback that touchscreens totally lack. [Garage Tinkering] on YouTube agrees; he also doesn’t like the way his aftermarket Kenwood head unit looks in his 2004-vintage Nissan. That’s why he decided to take matters into his own hands, and hack the buttons back on.

Rather than source a vintage stereo head unit, or try and DIY one from scratch, [Garage Tinkering] has actually hidden the modern touchscreen unit behind a button panel. That button panel is actually salvaged from the stock stereo, so the looks fit the car. The stereo’s LCD gets replaced with a modern color unit, but otherwise it looks pretty stock at the end.

Adding buttons to the Kenwood is all possible thanks to steering-wheel controls. In order to make use of those, the touchscreen head unit came with a little black box that translated the button press into some kind of one-wire protocol that turned out to be an inverted and carrier-less version of the NEC protocol used in IR TV remotes. (That bit of detective work comes from [michaelb], who figured all this out for his Ford years ago, but [Garage Tinkering] is also sharing his code on GitHub.) Continue reading “Hacking Buttons Back Into The Car Stereo” →

2025 Component Abuse Challenge: The Ever-Versatile Transistor As A Temperature Sensor

November 5, 2025 by 10 Comments

One of the joys of writing up the entries for the 2025 Component Abuse Challenge has come in finding all the different alternative uses for the humble transistor. This building block of all modern electronics does a lot more than simply performing as a switch, for as [Aleksei Tertychnyi] tells us, it can also function as a temperature sensor.

How does this work? Simple enough, the base-emitter junction of a transistor can function as a diode, and like other diodes, it shows a roughly 0.2 volt per degree voltage shift with temperature (for a silicon transistor anyway). Taking a transistor and forward biasing the junction with a 33 K resistor, he can read the resulting voltage directly with an analogue to digital converter and derive a temperature reading.

The transistor features rarely as anything but a power device in the projects we bring you in 2025. Maybe you can find inspiration to experiment for yourself, and if you do, you still have a few days in which to make your own competition entry.

2025 Hackaday Component Abuse Challenge

The Deadliest US Nuclear Accident Is Not What You Think

November 5, 2025 by 29 Comments

When you think of a US Nuclear accident, you probably think of Three Mile Island. However, there have been over 50 accidents of varying severity in the US, with few direct casualties. (No one died directly from the Three Mile Island incident, although there are some studies that show increased cancer rates in the area.)

Indeed, where there are fatalities, it hasn’t been really related to the reactor. Take the four people who died at the Surry Nuclear Power Plant accident: they were killed when a steam pipe burst and fatally scalded them. At Arkansas Nuclear One, a 525-ton generator was being moved, the crane failed to hold it, and one person died. That sort of thing could happen in any kind of industrial setting.

But one incident that you have probably never heard of took three lives as a direct result of the reactor. True, it was a misuse of the reactor, and it led to design changes to ensure it can’t happen again. And while the incident was nuclear-related, the radiation didn’t kill them, although it probably would have if they had survived their injuries. Continue reading “The Deadliest US Nuclear Accident Is Not What You Think” →